November 2008 Digital Group Meeting

Meeting Notes March 2009 to 2018.
Post Reply
spb
Posts: 146
Joined: Tue Mar 25, 2008 7:04 pm

November 2008 Digital Group Meeting

Post by spb » Fri Nov 07, 2008 9:48 pm

This turned out to be a very busy evening with much to discuss and plenty of interesting images to explore.

PC HOUSEKEEPING

This beginners lesson was a new topic for us covering Windows Explorer, filing systems, security and recommended housekeeping procedures. The freeware mentioned was the backup software SyncBack Freeware , the anti-virus software AVG Free and the registry cleaner CCleaner.

NEWS

Photoshop CS4 has been released with many enhancements but (in my opinion) nothing very exciting. Upgrade from CS3 is hardly compelling unless you have £160 burning a hole in your pocket. Upgrade from earlier versions of Photoshop may be more justifiable especially if you take raw images and your camera is not supported. If you have Photoshop CS this may be your last chance to qualify for an upgrade. If you have Photoshop 7 or earlier - my sympathies.

Photoshop Elements 7 has also been released. I'm sure that it's wonderful and will keep the Adobe coffers topped up.

SOURCES OF IMAGE QUALITY LOSS

Causes of quality loss in-camera include;
- camera shake
- under/over exposure
- ISO setting too high
- pixel count/image size set too low
- image quality/jpg compression set too low
- insufficient depth of field or wrong focus point

Causes of quality loss in Photoshop include;
- limited tonal range caused by inappropriate use of levels, curves, brightness, contrast, highlight, shadows etc.
- degredation caused by over processing the image ie repeatedly adjusting tones, repeatedly cloning the same area etc.
- over-sharpening
- poor colour management or printer setup.

ALTERNATIVE SENSOR SPOT FIX

The most common fixes for visible sensor dust spots are probably the clone or healing brush tools. Peter Jones demonstrated an alternative technique;

Duplicate the background layer then apply the Dust and Scratches filter, choosing a sufficiently high setting to hide the offending spots. In the History palette take a Snapshot and then undo the Dust and Scratches step. Select the History Brush and set it's source to the Snapshot. Brush over the spots with the History Brush to make them disappear.

THE BLUR FILTER

We discussed a problem that is often encountered with the blur filter. When blurring within a selection, the blurred edge may stray across the boundary of the selection to affect adjacent pixels which can cause an unnatural look. One way to avoid this is to select the part of the image to be blurred but then place it on it's own layer (Layer>New>Layer Via Copy). In the Layers palette ensure that this new layer is selected and then switch on the Lock Transparent Pixels button in the palette. When this layer is now blurred nothing will stray across the edge into surrounding transparent area.

KALEIDOSCOPE PROGRAM

Last month we looked at a simple kaleidoscope program. Pattern fans may be interested to know of a very much more sophisticated program called Kaleider. This is capable of producing the most amazing repeating, mirroring and distorting patterns based on any part of any image. Although a commercial program, Kaleider only costs about £20 and can be downloaded for a free trial.

FUTURE MEETINGS

The December 4th meeting will be dedicated to Audio Visuals. As well as a tutorial we will feature a couple of Barbara Fleming's AVs as well as the best of those that I can find in the public domain. If anyone has an AV to show us please let me know in advance.

I have also been experimenting with High Dynamic Range techniques using Photomatix software. This is capable of producing strange and remarkable images. When I have a little more experience with the technique I plan to demonstrate it to the digital group, hopefully early in the new year.

Cheers, Steve.

NB Don't forget that I can provide private tuition on Photoshop and other aspects of digital photography such as the PC Housekeeping covered in this meeting. Notes, homework and support are included on all topics

Post Reply